.top {
    position: relative;
    width: 100%;
    text-align: center;
    line-height: 60px;
    height: 60px;
    background-color: #555555;
    color: #fff;
}
.top  span img {
    display: none;
}
.top .pss {
  font-size: 18px;
  font-weight: 600;
    margin: 0 auto;
}
.one_li {
    display: block;
    position: absolute;
    left: 0;
    top: 0;
}
.top .ico {
    width: 60px;
    height: 60px;
  
    z-index: 99;
    position: relative;
}
.all_li {
 position: absolute;
 top: 60px;
 left: 0;
 width: 100px;
 background-color: #fff;
 height: 0;  
 display: block;
 z-index: 99;
 opacity: 1;
 overflow: hidden;
 transition: height 1s;
}
 .one_li:hover .all_li {
    height: 500px;
    background-color: #fff;
}


.banner {
   height: 200px ;
    width: 100%;
    background: url(../img/banner.jpg) no-repeat center;
    position: relative;
    background-size: 100%  100%;
}
.logo {
    color: #555;
    padding-top: 120px;
    text-align: center;
    transition: color .5s;
}
.logo:hover {
    color: red;
}
.nav {
    width: 100%;
    height: 820px;
    background-color: #fff;
   
}
.nav h1{
    background-color: #eee;
    text-align: center;
}
.nav img {
    width: 100%;
}
.nav .w {
display: flex;
flex-wrap: wrap;
justify-content: space-around;
}
.one {
   
    width: 48%;
    margin: 5px 0;
    /* float: left; */
    height: 250px;
    padding: 10px;
   background-color: #eee;
    
}

.fff {
    padding: 20px;
}
.footer {
    height: 50px;
background-color: #555;
    width: 100%;
}
.footer img {
    display: none;
    
}
.footer .w {
    display: none;
    position: relative;
}
.footer::after{
    content: 'cocoxuan';
    position: absolute;
    left: 50%;
   padding-top:10px ;
    transform: translate(-50%);
    color: #fff;
    font-size: 24px;
    
}